The present invention relates generally to a release assembly. More specifically, it relates to a clutch release assembly which releases a pull-type clutch by extracting the radially inward margin of its diaphragm spring in the direction of an associated transmission.
Conventional clutches of this type are composed of a clutch disc assembly and a clutch cover assembly having a diaphragm spring which urges a pressure plate toward the flywheel of a motor vehicle engine, and thus compresses the clutch disc between the pressure plate and the flywheel in order to engage the clutch. The release assembly to a pull-type clutch extracts the radially inward margin of the diaphragm spring toward the transmission in order to release the clutch.
A conventional release assembly for a pull-type clutch includes a release bearing whose inner race member extends in the axial direction and into a support member fixed onto the radially inward margin of the diaphragm spring. The extension of inner race member and the support member are fastened detachably through a wire ring.
The wire ring is fitted onto a wedge collar which is retained by the support member, and the extension of inner race member is either connected or disconnected to the support member. In releasing the clutch, the operating force in the inner race member is applied to the support member through the wire ring and the wedge collar. Since the cylindrical wedge collar is composed of stamped and folded sheet metal, the wedge collar is subject to breakage by the operating force during clutch release.
This has led to the disclosure of a release assembly for a pull-type clutch omitting the wedge collar in Japanese Patent Laying-Open No. 37522/1987. This release assembly includes a hub (support member) which is connected to the diaphragm spring and has an inner groove for retaining the wire ring. The groove is formed such that its diameter is greater than the outside diameter of the wire ring, to allow elastic expansion of the wire ring in the radial direction.
Before the release bearing is connected into the hub, the wire ring of the release assembly disclosed in the aforementioned document is held in axial retention by the groove of the hub, while, since its outside diameter is formed to be less than the maximum diameter of the groove, it has radial play. This play is taken up by the expansion of the wire ring into the groove of the hub during installation. Consequently, smooth connection of the release bearing into the hub is hindered since prior to installation the wire ring is out of coaxiality with the hub and the release bearing.